This was said by the Blessed One, said by the Arahant, as I have heard:
Bhikkhus, there are these two things that cause remorse. What are the two? Here, bhikkhus, a certain person has not done good, has not done what is |wholesome::healthy, beneficial, useful [kusala]|, has not protected others from fear, but has done evil, cruelty, and misdeeds. He feels remorse thinking, ‘I have not done what is good’ and also ‘I have done what is evil.’ Bhikkhus, these are the two things that cause remorse.
The Blessed One spoke on this matter. In this regard, it is said:
“Having done bad conduct by body,
and by speech;
Having done bad conduct by mind,
and other actions associated with |blame::ill-will, hate, hatred, fault, resentment [dosa]|.
Not having performed wholesome actions,
but having performed many unwholesome ones;
When the body breaks up, the undiscerning one,
|arises::is reborn, re-arises, appears as if placed [upapajjati]| in hell.”
This matter too was spoken by the Blessed One, as I have heard.